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Chapter 32: Electrostatics
32.1: Electrical Forces and Charges
  • Electrical charges have a force acting between that is similar to the force acting between two masses.
  • An electrical force can be attractive or repulsive unlike gravity
  • Charges with like signs will repel each other and charges with opposite signs will attract each other.

32.2: Conservation of Charge
  • Conservation of charge states that the total amount of charge both positive and negative is constant.
  • Charge cannot be created or destroyed and can only be transferred from one object to another.
  • If one object is given a positive charge something else must be given a negative charge of the same magnitude.

32.3: Coulomb’s Law
  • F=kC*q1q2/d2
  • Coulombs constant: kC = 9.0 * 109 N * m2/ C2
  • The direction of the force will be toward the other charge if the charges have opposite signs and away from each other if they have the same sign.

32.4: Conductors and Insulators
  • Some materials allow electrons to move easily and others restrict the movement of electrons
  • Materials that allow electrons to move freely are called conductors
  • Materials that restrict the movement of electrons are called insulators
  • Examples of conductors are metals; some examples of insulators include plastic, rubber and wood.

32.5: Charging by Friction and Contact
  • Objects can become electrically charged through contact
  • By rubbing together two dissimilar objects some of the electrons from one object will be drawn to the other.

32.6: Charging by Induction
  • Using an already charged object to charge another without contact is called induction
  • This can be done by taking a rubber rod near the object to be charged
  • Allow the displaced charge to drain off on the other side
  • Removing the drain while the charged object remains
  • Removing the original charged object leaving the induced charge

32.7: Charge Polarization
  • When an insulator is brought near a charged object the charges in the insulator will rearrange so that all the negative charges will be on one side and all the positive charges will be on the other
  • This causes the object to be electrically polarized
  • This will not change the net charge of the insulator but it will allow a small or light object to be lifted by a charged object.